Because many people aren't familiar with PGP encryption, a blog post about PGP, how it works and how to use it. This post is only a brief description about PGP and covers not all details. Pretty-Good-Privacy (PGP) is an encryption technology mainly used for sending encrypted email, but also in use to encrypt texts, files or even whole disk partitions. To use PGP you require a public and a private key. The public key, like the name suggests, can be shared with everybody. In contrast to that, the private key should be protected by a password and kept secret.
So if you want to send an email to a friend and no one else should be able to read this, you can use the public key from your friend and encrypt the message. The public key can be downloaded from a so called keyserver or you just ask your friend to share his public key. Afterwards you can send this message like a normal email and the recipient can decrypt the message with his private key. So only the owner of the private key is able to decrypt a with the public key encrypted message. To perform this, plugins are available for most email programs and many different platforms (Windows, OSX, Linux, Android, …).
Now I want do describe the configuration of PGP, for the email program Thunderbird. This program is available for multiple platforms and provides a plugin for PGP encryption. Therefore, the plugin Enigmail is required, which can be installed with the addon manager of Thunderbird. Afterwards you should restart Thunderbird and a wizard window should pop up. If this window doesn't show up, it's also possible to initialize the wizard by yourself. Just click in the menu of Thunderbird (Looks like three vertical lines in the upper right corner) on Enigmail → Setup Wizard.
The next step is to choose if you want assistance or not. For beginners it's the best choice to use the standard configuration. Afterwards the window shows that you have to install GnuPG. Just click Install GnuPG and the wizard will do it for you. This will show a window about the GnuPG installation, where you can just click Next at every step or maybe customize the options if you want. When the installation finished you can click Next in the Enigmail Wizard and choose the email address, for what you want to create a PGP keypair. It's also recommend to choose a strong password for the private key in that step. Also a good choice is to use a strong password and let Thunderbird store it in the password manager, in contrast to choose no password.
Thats it, you successfully finished the installation and you can use PGP to send encrypted mails to your friends. Every time you send an email there should be two buttons which are provided by Enigmail. One looks like a padlock and if you click this one, the email will be encrypted with the public key of the recipient of the mail. So there is the question how you get the public key of the recipient. For that reason there are keyserver available where you can store your public key and also look for keys of your friends.
Therefore, the menu of Enigmail contains a part called Key Management. In that window you can see which keys you already have imported, import new keys or publish your own public key to a keyserver. If you want to upload your public key, you just perform a right click on the entry in the Key Management part, which list your own email address and choose “Upload Public Keys to Keyserver”. Afterwards, a popup shows up and you can choose the keyserver. Per default there is already a keyserver selected. So you can just click Ok and the public key will be uploaded to this server.
If you want to sent me an encrypted mail you can download my public key from this link and also choose the Key Management entry in the Enigmail menu. Afterwards, you have to click on Edit → Import Keys from File and choose my public key. If you have any further questions about PGP and the setup feel free to contact me.
Some links about the setup of Enigmail and also detailed descriptions how PGP works.
http://www.explainthatstuff.com/encryption.html http://www.pgpi.org/doc/pgpintro/ https://en.wikipedia.org/wiki/Pretty_Good_Privacy http://searchsecurity.techtarget.com/definition/Pretty-Good-Privacy https://support.mozilla.org/en-US/kb/digitally-signing-and-encrypting-messages